I do not believe that as written they had romantic feelings for each other. The argument that I make with Harmony is that given the chance, they ABSOLUTELY have the potentional to have deep, real feelings for one another and WITHOUT A DOUBT would have had an amazingly strong romantic relationship. This is based on what we see in the friendship. Everything about their friendship not only reads as though they are a couple, but shows that were they to have romantic feelings for one another, they would ABSOLUTELY work together as a couple. So do they have feelings for each other? - Not romantic. Not as the book is written. But based on what we know from the book, what we see in the movies, and what we interpret from common sense, it's more than apparent that Harry and Hermione aka Harmony/Harmione is the only thing that makes sense romantically... WAY more sense than the crazy pairings that actually made it into the series.
There's atleast one Harmony scene in each movie that to me, looks like they have feelings for each other. Exp: the dancing scene in 7.01. But maybe that's just Dan and Emma's chemistry because JK Rowling never intended to show that they had any feelings for each other, hence the movies would'nt have wanted to show that either. But, then again, maybe it IS H/Hr's interactions, not just Dan/Emma's chemistry.
I think that at they have feelings for each other every now and then but most of the time they think of each other as siblings because they are very close and don't have siblings themselves and I think they risked there lives for each other because that's what siblings do for each other and they loved each other like siblings